Stoker



G. (A. KOHOUT Dec. 27, 1.949

STOKER 8 Sheets-Sheet l Filed May 19, 1945 Il HNI www LLL

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STOKER 8 Sheets-Sheet 6 Filed May 19, l945 Dec. 27, 1949 G. A. KQHoUT 2,492,585

l sT'okER Filed May 19, 1945 8 Sheets-Sheet 7 Patented Dec. 27, 1949 UNITED STATES PATENT QFFICE STOKER' George A. Knhout, Chicago, Ill.

Application May 19, 1945,. Serial No.7594,'7-11 19 '-(Jlainis. (Cl. '11b-38) My invention 'relates to stoke'rs and has for its object the provision of a novel combination of a fuel trough andV means utilizing inertia of the fuel and gasv jet propulsion to advance fuel in the trough from one end to the other end' thereof.

My invention contemplates the provision ofv a combined conveyor and grate with a power drive that effects advance of the fuel by giving' the conveyor such a reciprocating action that inertia of the loose body of particles. of solid fuel, such as coal or coke, causes it to move in onev direction and jets of gas, such as air are directed against the fuel particles so that they lift theV fuel and help it along in the desireddirectionof advance. These jets also supply air for com'- bustion of the fuel.

In a preferred form of my'invention, I' provideA a fuel inlet section at the front of the conveyor" which is made to project from the furnace in? position to carry a hopper to which fuel is supplied. The conveyor is so constructed and'. mounted that its reciprocating motion can take place freely without the necessity of building movable parts or special mechanism into the furnace.

It is also a purpose of my invention to provide a novel means for separating, water from Wet fuel in a Stoker ofrthetype described;

lt is a further purpose of .my invention to pro'- vide means at they discharge end of the Stoker for controlling the thickness of the' bedofl fuel on the grate7 such means comprising anadjustable gate member thatv constitutes anu inclined floor at the discharge end ofthe Stoker, the angle of inclination of whichis adjustablek to vary the' height of the discharge edge thereof whereby` the level of the discharge. is controlled! and. the.l thickness of the bed of, fuelis'determined..

lt is a further purpose of my invention to.. provide a movable gratemember with means,A for supplying air to the fuelbedtherethrough, said'f grate member being movedin suchmanner asto advance the fuel longitudinally from-the hoppen end. of the grate to the ash` discharging. end:l

thereof, said air being suppliedinsuch. atman-Y ner that streams thereof athigh velocity are.diA

rected upwardly at an oblique angle and'towardg the discharge end of the grate, whereby said st' ems of air cooperate with the means forA moving the grate to accelerate the movement of.v

2. ter, means 'for supplying-aime'the fuelbeci which is directly connected with trie'sii'a'ft themoto'r, that. drives the means 'for moving theA grate bodily back and forth through ei'iibl'e driving members such as beits and pulleys, so that in" case a 'failure in the driving mechanism for' the means ier moving the grate back 'anafortn elimini` develop, air will-'continue to be applied to the fuel' bed'so as 'to prevent to' tne'grate due to overheating the' same ifv si'ichV air" were not supplied.

l "other objects and advantages oi invention wiii appear asitne' description of the draw'- in'gs proceeds. I desire to have it' understood,

however, that I do 'not intend to limit myself to being taken substantially on the line 3-3 of Figure l;

Figure 4 isa section taken-onV the line 44 of Figure l;

Figure-5-isan endeview ofthe operating mechanismlfor the stoker on a largerscale than Figa `urel taken substantially from the line 5-"5'of Fig-ureI 1,'. Y

Figure Slis afragmentary sideelevational view of saidgoperating means; A

Figure 7 is a fragmentary plan View' partly broken away showing a portion of the operating:A

means for: reciprocating the -troughlike member embodying the grate` therein;

Figure 8`is-a section taken on the line 8;-8 of Fg-ure;

Figure 9.-is.a section takencon the line 9-9 of Figure Zbut on alarger scale'than Figure 2;

EigurelOis a'sectiontakenY on the'liney Ill-I0 of :Figure V1 but on-aularger'scale than'Figurel; Figure-r 11 is anenlarged perspective view of one" of the side rnemloersof the troughlike fuel supporting member.;

Figure 12. isa horizontalsection through the side member shown ini Figure 11 takensubstantially, on theline- IZ-IlL of v.Fig-ure.v 111;-

Figure 13 is a fragmentary top plan View of the grate on a larger scale than Figure 2;

Figure 14 is a fragmentary sectional view taken on the line ill-i4 of Figure S and somewhat enlarged;

Figure 15 is a sectional view through a modied form of bumper member;

Figure 16 is a sectional view on the line lli-I6 of Figure 15;

Figure 17 is a fragmentary sectional view illustrating a modified form of inlet for the fuel conveyor; and

Figure 18 is a sectional view on the line |8-l8 of Figure 17.

Referring in detail to the drawings, my improved stoker is shown as being applied to a furnace having a front wall 29 and a wall 2| opposite thereto, said walls along with the side Walls defining a fire box 22. The walls 20 and 2| are supported on ledge plates 23 and 24 respectively, said ledge plates forming the top walls of openings through which the inertia, jet propulsion Stoker extends as will be described below. The ledge plates extend between suitable foundation members such as the concrete foundations and are supported thereby, similar plates 26 also being mounted on said concrete foundation 25 and supporting the side walls including refractory members 21 and 28.

Mounted on a suitable support 29 are rails 3U which are substantially inverted T-shaped in cross section and with which the grooved wheels 3| cooperate. The wheels 3l are mounted on axles 32, which are mounted in depending bearing brackets 33, mounted on longitudinally extending re-enforcing bars 34 xed to the bottom wall 35 of an air supply chamber 35.

Said air supply chamber 36 has upstanding side walls 31 which are secured by means of longitudinally extending angle members 38 to the bottom plate 39 of the troughlike member I5 thus formed which has the grate mounted thereon. Said bottom plate is provided with a plurality of openings 40 therein in the area in which the grate is located, and openings 4i at the sides of the area in which the grate is located, said openings 46 and 4l being provided throughout the length of the grate. The parts 31, 38 and 39 are secured together rigidly in xed position by welding or in `any other suitable manner. The air chamber 36 is also provided with end walls 42 and 43 and with imperforate top walls 44 and 45 extending from said end walls to the perforated portion underneath the grate as will be obvious from Figures 1, 8 and 9. A boxlike chamber is thus provided for supplying air to the grate which is perforated only in the area thereof covered by the grate and at both sides of the grate. An air supply duct 46 leads through the top Wall 44 into the chamber 36 from a blower 41.

A plurality of transversely extending grate members 48 is provided to make up the grate portion of the movable troughlike member I5 that receives the fuel and conveys it from the fuel receiving end through to the discharge end thereof. Each of said grate members is provided with depending ribs 49 which rest on the bottom plate 39 and with a plurality of depending bosses 50 through which the headed screwthreaded securing elements 5I extend, said securing elements being screw-threadedly connected with the plate 39 and having the heads thereof countersunk in openings 53 in said grate member 48. A plurality of passages for air are provided in each of said grate members. These passages have short vertical inlet portions 54 leading to obliquely extending portions 55 which are inclined upwardly and toward the rear or discharge end of the grate and which lead into horizontally extending portions 58 which are substantially parallel to the top face portions 51 and 58 of said grate members. These passages direct jets of air into the bottom of the fuel bed on the grates. The parallel faces 58 and 51 of the grate surface are vertically spaced from each other, being connected by means of inclined cifset portions 59 which act as deflecting surfaces for air jets from the passages 56, deflecting the same` obliquely upwardly and rearwardly toward the discharge end of the furnace. The air jets exert `a lifting and propelling force on the fuel particles. Due to the provision of the depending ribs 49 and similar transversely extending depending ribs 66 on said grate member 48, an air chamber 6| is provided under each of said grate members 48 and between the same and the platelike member 39 to which the openings 40 supply `air from the chamber 35.

The grate portions which have the passages therein have the portions 58 and 59 thereof projecting upwardly above the portions 51 to thus provide hollow projections alternating with the depressed portions arranged in rows lengthwise of the stoker. Between said rows of alternating raised portions and projections are continuous ribs |68, the entire grate thereby having a ribbed eiect with air nozzles provided therein lying be- Y tween the ribs in said grate members 48.

Also mounted on the plate 39 are the side members 62 which are hollow blocklike members shown more clearly in Figures 3, l1 and l2, said hollow blocklike members having end walls 63 1 provided with ribs 64 and opposite end walls 65 that are provided with rabbets 66 with which the ribs 64 cooperate to hold said blocklike members in alignment. The blocklike members on opposite sides of the troughlike member are of a reverse construction. Each of the members has a vertically extending side wall 61 provided with an inwardly directed bottom flange 58 which is secured to the platelike member 39 in any suitable manner, and an inclined inner wall 69 which is connected with the vertical wall 58 by an upper transverse portion 10. The blocklikemembers shown in Figures 11 and l2 are those that are shown at the left hand side of Figure 3.

The base portion 1I of each of the inclined walls 89 is spaced from the edge of the iiange 53 to provide a longitudinally extending slotlike opening in the bottom of each of said blocks S2 aligning with the openings 4| so that air will flow from the chamber 35 into the chambers 12 provided in the interior of each of the blocklike members 62. At said base portion 1I the inner walls of said blockllke members are provided with short vertically extending portions 13 to nt up to the side edges of the grate members 48. The walls 59 are provided with generally slightly downwardly the side walls 31 of the chamber 36, suitable spacing means being provided between said members |35 and said side walls, as will be evident from Figure 7, said brackets having openings therein through which the screw threaded ends |36 of two rodlike members |31 extend. Said rodlike members slidably pass through openings in a cross bar |38 provided on the rockable plate |39. Said cross bar |38 can be made in the form of a flange integral with the member |39 or can be secured thereto in any suitable manner. The screw threaded ends |36 of the rods |31 are fixed to the brackets |35 adjustably by means of the nuts |40 and |4| engaging opposite faces of the bracket |35. Slidably mounted on each rodlike member |31 are sleevelike members |42, |43, and 44, said sleevelike members having stop flanges |45, |46 and |41 thereon which may be made by welding washers thereto. Mounted between the iianges |46 and |41 are compression coil springs |48, and mounted between said flanges |46 and the iianges |45 are compression coil springs |49. The initial compression on the springs |48 and |49 can be adjusted by means of an adjusting nut |50 and a lock nut |5| on each member |31, a washer |52 being provided between the nut |50 and the ange |45.

When the roller |25 is engaged by the high point on the cam |24 at the roller |53, the roller |25 having ridden along the gradually rising face |26 of the cam, said cam rotating in the direction indicated by the arrow in Figure 8, the roller |25 being stationary and the cam being mounted on the movable carriage comprising the troughlike member and other parts mounted on the wheels 3|, the troughlike member and the parts carried thereby will have been moved to the right as viewed in Figures 1, 2 and 7, thus moving the brackets |35 to the right and compressing the springs |48 and |49 between the cross bar |38 and the abutment provided by the flange |45. The sleevelike members |42, |43 and |44 tting within the coils of the springs |48 and |49 loosely will' prevent any bowing of the springs out of line, so that the axis of the coils of the springs will coincide with the axis of the rodlike members |31. After the roller |25 drops oif the high point of the cam around the roller |53, the compression on the springs will be suddenly relieved, causing rapid movement of the troughlike member and all parts moving therewith to the left in Figures 1, 2 and '7. When the springs |48 and |49 are compressed a rubber bumper member |55, which is mounted on a rodlike member |51 slidably extending through openings in the member |38 and a reenforcing disclike member |58, will be spaced from the member |38 due to the fact that such rodlike member is xed to a depending bracket |59 at the screw threaded end |60 thereof by means of two nuts |6| and |62. Accordingly when the troughlike member with which said bracket |59 moves, being secured to the bottom wall 35 of the air chamber 36, is projected rapidly toward the left, due to the dropping of the roller off the high point of the cam, the bumper member |55 will engage with the member |58 on the cross bar |38 and this will suddenly halt the movement of the troughlike member toward the left in Figures 1, 2 and 9. The initial compression of the member |55 can be adjusted by means of a nut |63 engaging the screw threaded end |64 of a rodlike member |51, a lock nut |65 being provided for holding the parts in adjusted position. The member |55 is compressed in a sleeve |56 to prevent circumferential expansion of the member when it is compressed endwise.

The platelike member |39 is mounted for a slight rocking movement about the axis of a shaft |66. The shaft |66 has a pair of bearings |61 mounted thereon which are mounted in two angle members |68 xed to the base member 29, said angle members being mounted on spacers |69 which rest upon the base member 29 (see AFigure 8) This bearing consists of a metal ring in which there is a rubber ring |6113, that is compressed by two tapered blocks |51a, entering the rings from opposite sides. This provides a yielding mounting for shaft |66. The shaft |66 is mounted between a pair of blocks |10 projecting upwardly from the platelike member |39 and fixed thereto, said blocks being bridged by means of a platelike member |1| to complete the mounting of the shaft |66 to the plate |39.

The plate |39 is mounted on front and rear cushions |12 and |13 so as to provide a exible mounting permitting a limited rocking motion of the plate |39 about the shaft |66. A pair of the cushion members |12 is provided at the rear end of the plate |59 and a pair of the cushion members |13 is provided at the forward end of the member |39. Said cushion members as will be obvious from Figures 5 and 14, each comprise a channel member |14 secured to the under side of the platelike member |39 and a pair of angle members |15 secured to the base plate 29. Between said channel |14 and the angles 15, pads of rubber or other compressible material |16 are provided, said channel members |14 and angle members |15 being molded in the bodies of rubber |16 so as to be fixed thereto.

Due to the yieldable mounting of the plate member |39, the compression of the springs |45 and |49 acting on the member |38 will have a tendency to force the forward end of the plate member |39 downwardly, compressing the members |13, this taking place gradually as the high point of the cam is approached by the roller |25. When the high point of the cam is passed, then the sudden engagement of the bumper member |55 with the member |58 on the transverse member |38 will exert a force on the plate |39 such as to tend to tilt the forward end thereof upwardly, compressing the cushion members |12.

As a result of the actuating mechanism and cushion means above described, the troughlike member I5 comprising the grate and the side members and the extensions thereon at the opposite ends thereof, will move at a gradual rate toward the right and will move suddenly toward the left and be stopped suddenly in the leitward movement thereof (as viewed in Figures l and 2 of the drawings) when the bumper member engages the member |56. The halting of the movement toward the left is cushioned by means of the member |55 and the cushion elements |12 which will cooperate to cushion the shock of the sudden stopping of the reciprocating parts of the Stoker. The sudden stop causes the fuel, due to the inertia thereof; to continue to move to the left after the leftward movement of the trough has been halted. Furthermore, the shock will be cushioned from the base plate and thus will not be transmitted to the building on which the base plate is mounted because of the provision of the cushion members |12 and |13. Whenever the motor is started to operate the cam mechanism for reciprocating the trough-like member and the parts moving therewith, the blower 41 will operate discharging air under suitable pressure ll -vtop face of said grate toward the discharge end thereof, and means on said grate for deilecting the air discharged on the top face thereof upwardly yat an oblique angle to said top face.

to move with said troughlike member, said projecting portion being closed at the top thereof,

and means for drying the fuel supplied to said troughlike member from said hopper, comprising airblast nozzles in said projecting portion communicating with the fuel in the projecting portion.

7. Means to advance fuel into a furnace comprising in combination a reciprocating fuel supporting trough with means to impart rapid repeated short reciprocatory movements thereto toward and away from the discharge end thereof, stop means for abruptly stopping the movement in the direction toward the discharge end, the fuel trough having its bottom composed of fuel supporting surfaces separated by air inlet nozzles all formed to direct jets of air up into the fuel bed and toward the discharge end of the trough, and means supplying air under pressure to said nozzles continuously during movement of the trough in both directions whereby to advance the fuel and lift it as it is being reciprocated in one direction and to retard return movement of the fuel upon reverse movement of the trough.

8. A stoker comprising a troughlike member forming a fuel support, said member having air jet nozzles in closely spaced relation in the bottom thereof, said nozzles being directed toward one end of the member, a carrier for said member, a hopper on said carrier, a fan on said carrier, means connecting said fan to said nozzles whereby to supply air under pressure thereto, and means to reciprocate said carrier.

9. A stoker comprising a troughlike member .having a fuel inlet at one end and an ash discharge outlet at the other end, means mounting said member for reciprocatory movement, and means to cause said member to advance toward its discharge end at an increasing rate of speed, stop suddenly and return toward its inlet end at a relatively slow rate, said means comprising springs urging the member in the first named direction, a stop member limiting the advance of .said member in the aforesaid direction, power means for moving said member in the opposite direction and releasing it, and a yielding bumper movable with the trough member to engage said stop member.

10. A Stoker comprising a troughlike member having a fuel inlet at one end and an ash discharge outlet at the other end, means mounting said member for reciprocatory movement; and means to cause said member to advance toward its discharge end at an increasing rate of speed, stop suddenly and return toward its inlet end at a relatively slow rate, said means comprising springs urging the member in the first named direction, a stop member limiting the advance of said member in the aforesaid direction, power means for moving said member in the opposite direction and releasing it, and yielding mounting means for said stop member, comprising a base plate, a second plate secured on the base plate l12 by yielding cushions and carrying the stopv member, and a shaft pivoting the second plate on the rst plate.

11. A Stoker comprising a troughlike member having a fuel inlet at one end and an ash discharge outlet at the other end, means mounting said member for reciprocatory movement, and means to cause said member to advance toward its discharge end at an increasing rate of speed, stop suddenly and return toward its inlet end at a relatively slow rate, said means comprising springs urging the member in the first named direction, a stop member limiting the advance of said member in the aforesaid direction, power means for moving said member in the opposite direction and releasing it, and yielding mounting means for said stop member.

l2. In a furnace, a wall having an opening therein, a movable troughlike member comprising a fuelsupporting grate mounted for reciprocation in said furnace, said troughlike member projecting through said opening, a hopper on said member outside the furnace wall, spring means to advance said member into the furnace, power means to withdraw the member a limited distance against the force of said spring means, and cushion stop means for suddenly stopping said member in its advance by the springs, said cushion stop means comprising two telescoping tapered members and a yielding high friction lining between them.

13. In a furnace, a wall having an opening therein, a movable troughlike member comprising a fuel supporting grate mounted for reciprocation in said furnace, said troughlike member projecting through said opening, a hopper on said member outside the furnace wall, spring means to advance said member into the furnace, power means to withdraw the member a limited distance against the force of said spring means, and cushion stop means for suddenly stopping said member in its advance by the springs, said stop means comprising a resiliently mounted and pivoted stop bar.

14. A grate structure for furnaces adapted to advance particles of solid fuel of mixed sizes through a combustion zone, and to discharge the ash residue, comprising a trough structure embodying a bottom wall and side walls, power means to move said trough endwise to and fro in such manner as to impart a greater travel of fuel particles thereon toward the discharge end of the trough, air jet nozzles in the bottom wall of said trough directing air under pressure upwardly and toward the discharge end of said trough, means supplying said nozzles with air under presslue and air inlets in said'side walls directed toward said discharge end and down- Wardly.

15. In a furnace, a wall having an opening therein, a movable troughlike member comprising a fuel supporting grate mounted for reciprocation in said furnace, said troughlike member projecting through said opening, a hopper on said member exteriorly of said wall, a fan carried on said member, and a forced air duct on said member leading from said fan.

16. In a furnace, a wall having an opening therein, a movable troughlike member comprising a fuel supporting grate mounted for reciprocation in said furnace, said troughlike member projecting through said opening, a hopper on said member exteriorly of said wall, a fan carried on said member, a motor on said member 13 for reciprocating said member, and a forced air duct on said member leading from said fan.

.17. A Stoker comprising a troughlike member having a fuel inlet at one end, an ash discharge outlet at the other end and a fuel supporting grate therebetween, means mounting said member for reciprocatory movement, and power means connected in driving relationship with the troughlike member to advance said member toward its discharge end and then to return said member toward its inlet end, a stop member for abruptly stopping the advance of said member toward its discharge end before the member is moved in its return direction, a blower on the inlet side of the member, and means directing air from said blower through said grate in a direction toward the discharge end of said troughlike member.

18. A Stoker comprising a troughlike member having a fuel inlet at one end, an ash discharge outlet at the other end, and a fuel supporting grate therebtween, a hopper mounted on the troughlike member for supplying fuel to said troughlike member, means mounting said member for reciprocatory movement, and power means connected in driving relationship with. the troughlike member to advance said member and the hopper toward its discharge end and then to return said member and the hopper toward its inlet end, a stop member for abruptly stopping the advance of said member toward its discharge end before the member is moved in its return direction, a blower on the inlet side of the member, and means directing air from said blower through said grate in a direction toward the discharge end of said troughlike member.

19. A stoker comprising a troughlike member having a fuel inlet at one end, an ash discharge outlet at the other end and a fuel supporting grate therebetween, means mounting said member in reciprocatory movement, and power means connected in driving relationship with the troughlike member to advance said member toward its discharge end and then to return said member toward its inlet end, a stop member for abruptly stopping the advance of said member toward its discharge end before the member is moved in its return direction, a blower on the inlet side of the member, and means directing air from said blower and against the fuel supported on the grate, the direction of said air against the fuel being toward the discharge end of said troughlike member so as to exert a force tending to move the fuel in said direction.

GEORGE A. KOHOUT.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 527,593 Coxe Oct. 16, 1894 1,151,138 Van Vleck Aug. 24, 1915 1,481,366 Herkenrath Jan. 22, 1924 1,582,127 Cope Apr. 27, 1926 1,582,951 Wedge May 4, 1926 1,651,026 Herkenrath Nov. 29, 1927 1,802,960 Simonds Apr. 28, 1931 1,947,831 Davidson Feb. 20, 1934 2,033,570 Cruikshank Mar. 10, 1936 2,120,046 Tretheway June 7, 1938 2,170,277 Richardson Aug. 22, 1939 2,261,540 Coder Nov. 4, 1941 2,311,373 Durning Feb. 16, 1943 2,340,190 Kohout Jan. 25, 1944 2,375,743 Lancaster May 8, 1945 FOREIGN PATENTS Number Country Date 226,725 Great Britain Apr. 23, 1924 357,916 Great Britain Oct. 1, 1931 638,961 France Feb. 28, 1928 697,459 Germany Oct. 15, 1940 

